Today, in the Internet era, the popularity of multimedia communications services continues to grow at extraordinary rates and provides users with a variety of platforms to access content. Consequently, the demand for increased capacity in communications networks (e.g., core data transport networks) continues to grow to enable and maintain the user experience at the highest levels. For service providers, core data transport networks are optical networks based on fiber-optic technologies. For example, QAM is a well-known advanced signal modulation technique that increases the capacity of optical networks.
Coherent optical detection is another well-known technique that is useful for detecting and demodulating received optical signals transmitted across optical networks. For example, coherent detection with digital signal processing (DSP) not only enables the deployment of complex modulation formats and polarization-division-multiplexing (PDM) that dramatically enhances per-channel capacity, but also provides wavelength selectivity features.
Therefore, a need exists for an improved channel and carrier recovery scheme that achieves increased overall processing performance and reduced hardware configuration complexity.